Make user nullable

Author: Volodymyr Chernyshov

CHANGELOG.md

@@ -12,6 +12,7 @@
 -->
 ## Master
 - Update `Kotlin` to `1.7.0` and added support for Apple Silicon Chipset [@gianluz] - [#231](https://github.com/danger/kotlin/pull/231)
+- Make user property nullable for cases when non BB user did a commit [@vchernyshov]
 
 # 1.1.1
 - Make GitLab approvals_before_merge variable nullable [#227](https://github.com/danger/kotlin/pull/227)

danger-kotlin-library/src/main/kotlin/systems/danger/kotlin/models/bitbucket/BitBucketCloud.kt

@@ -63,7 +63,7 @@ data class BitBucketCloud(
         @Serializable
         data class Author(
             val raw: String,
-            val user: User
+            val user: User?
         )
     }
 
@@ -99,7 +99,7 @@ data class BitBucketCloud(
         data class Participant(
             val approved: Boolean,
             val role: Role,
-            val user: User
+            val user: User?
         ) {
 
             @Serializable